Penetration of the egg' zona pellucida by the sperm cell is a process driven by hydrolytic enzymes.
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The critical step in fertilization is binding between sperm receptors and glycoproteins on the zona pellucida. This is the trigger for the acrosome reaction which includes an influx of CA and a rise in pH and cAMP levels within the sperm head. As a result, the plasma membrane of the sperm fuses with the outer acrosomal membrane and the exocytosis of the acrosomal<span> vesicle occurs. Components of the acrosome, like hydrolytic enzymes, are released and they degrade the <span>zona pellucida allowing</span> the sperm to move </span>inside.</span>
Answer:
The answer is D) Generate the energy required for lipids to diffuse through the membrane.
Explanation:
Membrane proteins don't produce energy in any required process inside the cell. Therefore, is not a function to generate the energy that lipids require to diffuse to the membrane. Although membrane proteins develop many functions, producing energy isn't one of them.
B. Coding sequences that regulate gene expression
If I’m not mistaken, A & C is intron.
C.Directly away from the Sun.
Explanation:
The umbra of Earth’s shadow is about 1.4 million km (860,000 mi) long and points directly away from the sun. A giant screen placed in the shadow at the average distance of the moon would reveal a dark umbra about 9000 km (5700 mi) in diameter, and the faint outer edges of the penumbra would mark a circle about 16,000 km (10,000 mi) in diameter. For comparison, the moon’s diameter is only 3476 km (2160 mi). Consequently, when the moon’s orbit carries it through the umbra, it has plenty of room to become completely immersed in shadow.
